Neem oil works in most situations.
Dish soap and water spray works on some pests/
Always identify the pest prior to doing anything. Try calling on your local county extension service, these folks are paid by the state to ease homeowner gardening problems, and are supposed to be up on the latest solutions to aid your quest.
Diatomaceous earth(diatoms), pryrthrin (chrysanthemums), rotenone, insecticidal soap or your own homemade mixture of hot peppers, garlic and the dead bodies of the pest that you are battling ground up in a blender and applied or hand picking and disposal.
